MYSTERY OF WILLILE CROSS - TEXAS

I'm hoping someone out there might be able to solve the question that has confounded our family for many, many years!!

It is truly a MYSTERY - where did Willie Cross (b: abt. 1851) come from?? Who were his parents, his siblings?? Some records show he was born in GA, some show TX and one even shows FL. He married Casalonia 'Cassie' Richey Sanders on February 24, 1878, Falls County, and had two children, William Franklin Cross (my grandfather) and Sallie Richie Cross Marlin. (The 1880 census for Falls County shows Willie and wife 'Carrie', we've discovered this is wrong, her name was definitely Cassie). When the children were very little, all records of Cassie disappear, Willie shows up next in Conroe where he married Jennie Maines. She later married Jackson Young but there's no death or divorce information for Willie. That's the MYSTERY - WHO WAS WILLIE, WHERE DID HE COME FROM and WHAT HAPPENED TO WILLIE CROSS???

I still haven't found anything about what happened to Willie or Cassie - it's still a mystery. To be honest I lost interest in everything when my son died April 2012, leaving 3 small children & I've just recently started poking around again. Just not sure where to go from here.